L-Alaninium tartrate

In the title compound, C₃H₈NO₂⁺·C₄H₅O₆⁻, the L-alanine mol­ecule exists in the cationic form, with a positively charged amino group and an uncharged carboxyl­ic acid group. The tartaric acid mol­ecule exists in the mono-ionized state. The structure is stabilized by a three-dimensional network of O—H...O and N—H...O hydrogen bonds. No head-to-tail hydrogen bond is observed among the amino acid mol­ecules. The aggregation pattern observed in the structure has striking similarities to those observed in other related amino acid–tartaric acid complexes.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.044
• wR factor = 0.114
• Data-to-parameter ratio = 6.5

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



STRVAL_01
         From the CIF: _refine_ls_abs_structure_Flack   -0.100
         From the CIF: _refine_ls_abs_structure_Flack_su    1.900
           Alert C Flack test results are meaningless.

PLAT_031  Alert C Refined Extinction Parameter within Range ....       3.21 Sigma

General Notes



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           24.96
         From the CIF: _reflns_number_total                954
         Count of symmetry unique reflns          953
         Completeness (_total/calc)            100.10%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured         1
         Fraction of Friedel pairs measured     0.001
         Are heavy atom types Z>Si present           no
          Please check that the estimate of the number of Friedel pairs is
          correct. If it is not, please give the correct count in the
          _publ_section_exptl_refinement section of the submitted CIF.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 2 Alert Level C = Please check

---

Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: CAD-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 1999); software used to prepare material for publication: SHELXL97.

L-alaninium tartrate

Crystal data

C3H8NO2^+·C4H5O6^−	F(000) = 252
Mr = 239.18	Dx = 1.521 Mg m^−3 Dm = 1.53 Mg m^−3 Dm measured by flotation in a mixture of xylene and carbon tetrachloride
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 25 reflections
a = 5.1446 (8) Å	θ = 2.8–25.0°
b = 13.721 (3) Å	µ = 0.14 mm^−1
c = 7.4751 (9) Å	T = 293 K
β = 98.09 (1)°	Plates, colourless
V = 522.42 (14) Å^3	0.35 × 0.30 × 0.15 mm
Z = 2

Data collection

Enraf-Nonius CAD-4 diffractometer	944 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.018
Graphite monochromator	θmax = 25.0°, θmin = 2.8°
ω–2θ scans	h = 0→6
Absorption correction: ψ scan (North et al. 1968)	k = 0→16
Tmin = 0.952, Tmax = 0.979	l = −8→8
1061 measured reflections	2 standard reflections every 200 reflections
954 independent reflections	intensity decay: <2%

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.044	w = 1/[σ^2(Fo^2) + (0.0848P)^2 + 0.196P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.114	(Δ/σ)max < 0.001
S = 1.07	Δρmax = 0.40 e Å^−3
954 reflections	Δρmin = −0.30 e Å^−3
146 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.045 (14)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983)
Secondary atom site location: difference Fourier map	Absolute structure parameter: −0.1 (19)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)

are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factorsbased on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.1688 (6)	0.5120 (3)	0.7325 (4)	0.0490 (9)
H1	0.1520	0.4853	0.8283	0.074*
O2	0.5462 (5)	0.5643 (2)	0.8841 (4)	0.0434 (7)
O3	0.1891 (5)	0.8233 (2)	1.3666 (3)	0.0371 (7)
H3	0.1219	0.8269	1.4595	0.056*
O4	−0.1330 (6)	0.7148 (3)	1.2868 (3)	0.0459 (8)
O5	−0.0059 (5)	0.6910 (2)	0.9597 (3)	0.0355 (6)
H5	−0.1203	0.6687	1.0140	0.053*
O6	−0.1078 (5)	0.90422 (19)	0.9821 (3)	0.0306 (6)
H6	−0.2144	0.8816	0.9008	0.046*
O7	0.4473 (4)	0.8258 (2)	0.7834 (3)	0.0330 (6)
O8	0.0315 (4)	0.8467 (2)	0.6604 (3)	0.0329 (6)
N1	0.6550 (6)	0.6760 (2)	0.6067 (4)	0.0314 (7)
H1A	0.6216	0.7198	0.6883	0.047*
H1B	0.6782	0.7063	0.5048	0.047*
H1C	0.7998	0.6431	0.6488	0.047*
C1	0.3949 (7)	0.5587 (3)	0.7495 (5)	0.0305 (8)
C2	0.4315 (8)	0.6077 (3)	0.5704 (5)	0.0354 (8)
H2A	0.2729	0.6452	0.5277	0.042*
C3	0.4727 (13)	0.5341 (4)	0.4281 (7)	0.0680 (18)
H3A	0.4944	0.5673	0.3181	0.102*
H3B	0.3230	0.4918	0.4070	0.102*
H3C	0.6270	0.4964	0.4683	0.102*
C4	0.0555 (6)	0.7650 (3)	1.2559 (4)	0.0262 (7)
C5	0.1493 (6)	0.7578 (3)	1.0720 (4)	0.0256 (7)
H5A	0.3315	0.7349	1.0893	0.031*
C6	0.1387 (6)	0.8580 (2)	0.9813 (4)	0.0217 (7)
H6A	0.2735	0.8992	1.0496	0.026*
C7	0.2117 (6)	0.8436 (2)	0.7923 (4)	0.0215 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0533 (18)	0.060 (2)	0.0355 (15)	−0.0295 (16)	0.0111 (12)	0.0073 (14)
O2	0.0405 (15)	0.0521 (17)	0.0370 (15)	−0.0132 (13)	0.0031 (12)	0.0158 (13)
O3	0.0431 (13)	0.0515 (17)	0.0194 (11)	−0.0106 (13)	0.0135 (10)	−0.0046 (12)
O4	0.0540 (16)	0.058 (2)	0.0300 (13)	−0.0215 (15)	0.0212 (12)	−0.0022 (12)
O5	0.0498 (14)	0.0334 (13)	0.0255 (13)	−0.0115 (12)	0.0129 (11)	−0.0048 (11)
O6	0.0291 (12)	0.0371 (14)	0.0274 (12)	0.0068 (10)	0.0105 (9)	−0.0082 (11)
O7	0.0269 (12)	0.0476 (16)	0.0269 (11)	0.0013 (11)	0.0127 (9)	−0.0042 (11)
O8	0.0300 (12)	0.0512 (16)	0.0191 (11)	0.0002 (12)	0.0085 (9)	−0.0020 (11)
N1	0.0354 (14)	0.0376 (16)	0.0244 (13)	−0.0106 (13)	0.0154 (11)	0.0011 (12)
C1	0.0336 (18)	0.0248 (16)	0.0356 (18)	−0.0061 (14)	0.0137 (14)	0.0002 (15)
C2	0.039 (2)	0.0349 (19)	0.0329 (18)	−0.0091 (16)	0.0083 (14)	0.0035 (15)
C3	0.110 (5)	0.056 (3)	0.045 (3)	−0.043 (3)	0.037 (3)	−0.020 (2)
C4	0.0292 (15)	0.0302 (16)	0.0204 (15)	0.0014 (15)	0.0075 (12)	0.0054 (14)
C5	0.0282 (15)	0.0313 (18)	0.0179 (14)	0.0009 (14)	0.0055 (11)	−0.0005 (14)
C6	0.0209 (14)	0.0261 (15)	0.0193 (14)	−0.0006 (12)	0.0072 (11)	−0.0040 (12)
C7	0.0260 (15)	0.0202 (14)	0.0201 (14)	−0.0028 (13)	0.0093 (11)	−0.0013 (12)

Geometric parameters (Å, º)

O1—C1	1.319 (5)	N1—H1B	0.8900
O1—H1	0.8200	N1—H1C	0.8900
O2—C1	1.185 (5)	C1—C2	1.533 (5)
O3—C4	1.279 (4)	C2—C3	1.503 (6)
O3—H3	0.8200	C2—H2A	0.9800
O4—C4	1.238 (4)	C3—H3A	0.9600
O5—C5	1.412 (4)	C3—H3B	0.9600
O5—H5	0.8200	C3—H3C	0.9600
O6—C6	1.418 (4)	C4—C5	1.522 (4)
O6—H6	0.8200	C5—C6	1.530 (5)
O7—C7	1.247 (4)	C5—H5A	0.9800
O8—C7	1.256 (4)	C6—C7	1.525 (4)
N1—C2	1.479 (5)	C6—H6A	0.9800
N1—H1A	0.8900
C1—O1—H1	109.5	C2—C3—H3C	109.5
C4—O3—H3	109.5	H3A—C3—H3C	109.5
C5—O5—H5	109.5	H3B—C3—H3C	109.5
C6—O6—H6	109.5	O4—C4—O3	126.2 (3)
C2—N1—H1A	109.5	O4—C4—C5	119.3 (3)
C2—N1—H1B	109.5	O3—C4—C5	114.5 (3)
H1A—N1—H1B	109.5	O5—C5—C4	110.8 (3)
C2—N1—H1C	109.5	O5—C5—C6	109.7 (2)
H1A—N1—H1C	109.5	C4—C5—C6	110.2 (3)
H1B—N1—H1C	109.5	O5—C5—H5A	108.7
O2—C1—O1	125.4 (3)	C4—C5—H5A	108.7
O2—C1—C2	124.5 (3)	C6—C5—H5A	108.7
O1—C1—C2	110.1 (3)	O6—C6—C7	113.5 (2)
N1—C2—C3	111.9 (4)	O6—C6—C5	112.1 (3)
N1—C2—C1	107.8 (3)	C7—C6—C5	107.2 (3)
C3—C2—C1	111.8 (4)	O6—C6—H6A	107.9
N1—C2—H2A	108.4	C7—C6—H6A	107.9
C3—C2—H2A	108.4	C5—C6—H6A	107.9
C1—C2—H2A	108.4	O7—C7—O8	125.5 (3)
C2—C3—H3A	109.5	O7—C7—C6	116.3 (3)
C2—C3—H3B	109.5	O8—C7—C6	118.2 (3)
H3A—C3—H3B	109.5
O2—C1—C2—N1	−10.8 (5)	O5—C5—C6—O6	72.3 (3)
O1—C1—C2—N1	167.7 (3)	C4—C5—C6—O6	−49.9 (3)
O2—C1—C2—C3	112.5 (5)	O5—C5—C6—C7	−52.9 (3)
O1—C1—C2—C3	−69.0 (5)	C4—C5—C6—C7	−175.1 (2)
O4—C4—C5—O5	0.4 (4)	O6—C6—C7—O7	163.2 (3)
O3—C4—C5—O5	179.0 (3)	C5—C6—C7—O7	−72.5 (3)
O4—C4—C5—C6	122.0 (4)	O6—C6—C7—O8	−19.5 (4)
O3—C4—C5—C6	−59.3 (4)	C5—C6—C7—O8	104.8 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O6^i	0.82	1.84	2.651 (4)	169
O6—H6···O7^ii	0.82	1.99	2.765 (4)	158
O5—H5···O4	0.82	2.15	2.639 (3)	119
O5—H5···O2^ii	0.82	2.34	2.878 (4)	124
O3—H3···O8^iii	0.82	1.66	2.466 (3)	170
N1—H1A···O7	0.89	1.90	2.740 (4)	157
N1—H1C···O5^iv	0.89	2.49	2.958 (4)	114
N1—H1B···O4^v	0.89	2.01	2.815 (4)	149

Symmetry codes: (i) −x, y−1/2, −z+2; (ii) x−1, y, z; (iii) x, y, z+1; (iv) x+1, y, z; (v) x+1, y, z−1.